CODEWITHSUNDEEP
c#
Deadly
Deadly

Reputation: 2094

Get child class properties in parent constructor

class A
{
    public string PropA {set; get;}

    public A()
    {
        var props = this.GetType().GetProperties(BindingFlags.Public);
    }
}


class B : A
{
    public string PropB {set; get;}
}

var b = new B();

When A constructor is called, variable props contains only PropA. It's possible to get all properties (PropA and PropB)?

Upvotes: 0

Views: 732

Answers (5)

Anders Marzi Tornblad
Anders Marzi Tornblad

Reputation: 19305

A base class is not supposed to know anything about its derived classes. It breaks the Open Closed Principle and the Liskov Substitution Principle.

You solve this using generics and virtual or abstract methods. Also, don't be writing your own O/R Mapper. There are so many out there, that some must cover your needs!

Upvotes: 0

Azhar Khorasany
Azhar Khorasany

Reputation: 2709

You could do:

class A
{
    public string PropA {set; get;}

    public A()
    {
    }

    protected virtual PropertyInfo[] GetProperties()
    {
        return this.GetType().GetProperties(BindingFlags.Public);
    } 
}


class B : A
{
    public string PropB {set; get;}

    public B() : base()
    {
    }

    public new PropertyInfo[] GetProperties()
    {
        return this.GetType().GetProperties(BindingFlags.Public);
    }
}

var b = new B();
var prop = b.GetPropeties();

Upvotes: 0

max
max

Reputation: 34407

This one works for me:

var props = this.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);

Upvotes: 2

Fischermaen
Fischermaen

Reputation: 12458

The constructor of base class A is run before the constructor of the derived class B, so you can not access the properties of the derived class.

BTW: This doens't make sense to me, that a base class has knowledge of the derived classes!

Upvotes: 0

Massimiliano Peluso
Massimiliano Peluso

Reputation: 26737

The Parent class(where you have defined the constructor) does not know anything about its child class that's why it returns just PropA If you define the constractor in the B class it will return both the properies

Upvotes: 0

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